recursion example

recursion/Fib.Mod

@@ -0,0 +1,33 @@
+MODULE fibonacci;
+
+
+IMPORT Out, Modules;
+
+
+VAR
+    n       : LONGINT;
+    Arg0    : LONGINT;
+
+
+PROCEDURE getFib (n : LONGINT) : LONGINT;
+    VAR result : LONGINT;
+BEGIN
+    IF n = 0 THEN
+        result := 0
+    ELSIF n = 1 THEN
+        result:= 1
+    ELSE
+        result := getFib(n-1) + getFib(n-2)
+    END;
+    RETURN result
+END getFib;
+
+
+BEGIN
+    IF Modules.ArgCount # 2 THEN
+        Out.String("one argument needed"); Out.Ln;
+        HALT(1);
+    END;
+    Modules.GetIntArg(1, Arg0);
+    Out.Int(getFib(Arg0), 0); Out.Ln;
+END fibonacci.

recursion/Gcd.Mod

@@ -0,0 +1,31 @@
+MODULE gcd;
+
+
+IMPORT Out, Modules;
+
+
+VAR
+    gcd         : INTEGER;
+    arg0, arg1  : LONGINT;
+
+
+PROCEDURE getGCD(a, b : INTEGER): INTEGER;
+VAR ret : INTEGER;
+BEGIN
+    IF a = 0 THEN ret := b;
+    ELSIF b = 0 THEN ret := a;
+    ELSIF b > a THEN ret := getGCD(b, a);
+    ELSE ret := getGCD(b, a MOD b) END;
+    RETURN ret;
+END getGCD;
+
+
+BEGIN
+    IF Modules.ArgCount # 3 THEN
+        Out.String("enter two integers to get GCD"); Out.Ln;
+        HALT(1)
+    END;
+    Modules.GetIntArg(1, arg0); Modules.GetIntArg(2, arg1);
+    gcd := getGCD(SHORT(arg0), SHORT(arg1));
+    Out.Int(gcd, 0); Out.Ln;
+END gcd.